This invention relates to water retaining surrounds for plants such as trees.
It is known to provide a water-retaining surround for plants.
An example of such a surround is described in U.S. Pat. No. 5,566,503 in the name of Nickson.
There is described in this United States patent a water retaining enclosure formed around a plant by a flexible wall of water impervious material. The wall is described as having projections at intervals on a first side and recesses on the other or second side to engage at least some of said projections for sealingly securing opposite end portions of the wall together.
The wall is described as being formed by extrusion and as being generally flat and being made from flexible plastics material and having as an essential feature a plurality of vertically extending projections distributed at regular intervals along a first side of the wall and a plurality of vertically extending recesses defined at regular intervals along the other side of the wall. These projections are resiliently received and gripped within respective recesses to effect a sealing engagement. This arrangement has the advantage that the overall diameter of the surround can be selected by joining some of the projections with a different set of the recesses.
One problem with such an arrangement however is that the appearance is less aesthetically favourable because of the plurality of vertical recesses and projections being visible. Further however by having a flat member that will be implicitly need to bent into and then be held in a circular shape means that there will be persistent pressure to release the joined ends because the plastic sheet wants to straighten out This means that the ends will be held against a persistent release resilient pressure. Plastics materials have an implicit characteristic of creeping under constant pressure and herein then lies the problem. With a surround that will be normally in the open environment and subject to extremes of weather means that the plastics material may becomes very heated. This then will result in aggravated deterioration of the assembled form.
An object of this invention is to reduce at least to some extent one or more of the above problems.
The invention accordingly can be said to reside in a plant surround comprised of a circular moulding of plastics material which is discontinuous, and has interfering surfaces between ends of the discontinuous shape which define the discontinuous zone, the surfaces at the respective ends being relatively slidable along their respective longitudinal alignment to effect an interlocking joining between the ends to provide a water retaining surround.
This then reduces the problem of persistent pressure by having the circular shape moulded and overcoming resultant other difficulties in different ways which give of themselves advantages.
If a moulding is of polymeric material and the wall is flexible, the polymeric moulding can give a high degree of water retention even if some leakage does take place at the discontinuous zone, but the flexible wall can be so distorted that the interfering surfaces can disengage by sliding in the axial zone, and the moulding can be xe2x80x9csprung openxe2x80x9d to be removed from the trunk of the tree.
In preference a lower edge of the moulding is shaped to have a number of xe2x80x9cbluntxe2x80x9d spikes. This is found to assist in the edge being able to enter the ground. This can, for example, be achieved by having a scalloped lower edge.
In preference the tree surround comprises a circular wall formed from flexible polymeric material such as polyethylene or polypropylene, the wall having a curvature in section, and having a larger diameter near its lower edge than near its upper edge.
In preference the upper edge is directed radially inwardly in the form of a flange.
In preference said plant includes a tree.
In preference one edge of the wall terminates in a bulbous bead, and with the ends joined, the bead is located in a space defined by a curved flange along the other edge to allow a relative longitudinal sliding action to effect a separating between the two edges and is not easily-separable other than by such sliding action.